[2B01-05] Decommissioning of Fukushima Daiichi NPP 1

[2B05] Development of ultramicro analysis technology for fuel debris analysis

(13) Dissolution behaviors of simulated debris with different
uranium/zirconium ratios by using alkaline fusion method

*ZhuoRan Ma¹, Hiroyuki Kazama³, Yoshiya Homma², Kenji Konashi², Tatsuya Suzuki¹ (1. Nagaoka Univ. of Tech., 2. Tohoku Univ., 3. JAEA)

Keywords:simulated debris, alkaline fusion, Dissolution

The dissolution of nuclear fuel debris generated from Fukushima nuclear power plant accident is necessary for the accurate and precise analyses of actinides and fission products. We have proposed the chemical conversion of insoluble nuclear fuel debris into soluble substances by alkaline fusion method. In the present work, the dissolution behavior in Nitric acid and Hydrochloric acid of simulated nuclear debris including UO₂-ZrO₂ by alkaline fusion reaction with reagent Na₂O₂ were studied. For the simulated debris with U-Zr mole ratio of 1 to 1 and sintered for 10 minutes at 1400℃, they were ground and mixed with Na₂O₂ with mass ratio of 1 to 10. After heating at 650℃ for 1 hour, they were dissolved with 6mol/l nitric acid. The dissolution rate reached more than 99% by the weight of residue after pressure filtration.